February 13, 2018—KB4074597 (Security-only update)

Applies to: Windows 8.1Windows Server 2012 R2

Improvements and fixes


This security update includes quality improvements. No new operating system features are being introduced in this update. Key changes include:

  • Addresses issue where after installing KB4056895 or KB4056898 on an SMB server, accessing files in directory junction points or volume mount points hosted on the server may fail. The error is “ERROR_INVALID_REPARSE_DATA”. For example, the following symptom may be observed:

    Editing some group policies using GPMC or AGPM 4.0 may fail with the error "The data present in the reparse point buffer is invalid. (Exception from HRESULT: 0x80071128)".

  • Addresses issue where, when SharePoint writes to a SQL Server filestream share with SMB3 encryption enabled, the write may fail or execute very slowly.

  • Security updates to Windows Kernel, Common Log File System driver, Windows storage and file systems, Microsoft Windows Search component, and the Windows SMB Server.

For more information about the resolved security vulnerabilities, see the Security Update Guide.

Known issues in this update


Symptom Workaround
Because of an issue that affects some versions of antivirus software, this fix applies only to computers on which the antivirus ISV updated the ALLOW REGKEY.

This issue is resolved in KB4093115. You no longer need the following ALLOW REGKEY to detect and be offered this update: 

HKEY_LOCAL_MACHINE"Subkey="SOFTWARE\Microsoft\Windows\CurrentVersion\QualityCompat\cadca5fe-87d3-4b96-b7fb-a231484277cc

How to get this update


This update is now available for installation through WSUS. To get the standalone package for this update, go to the Microsoft Update Catalog website.

File information

For a list of the files that are provided in this update, download the file information for update 4074597.